Marvell chip claims to make PCs more energy efficient

Mark this down as a little out there, but a new Marvell chip claims to improve the efficiency of desktop and laptop power supplies by determining and then optimizing the amount of energy each particular application needs. Named a "power factor correction controller," the chip enables computers to comply with new Energy Star guidelines that require computers to use at least 80 percent of the energy supplied to power them. It's not the only chip out there that claims to improve efficiency using this method, although Marvell has already started producing the chips with the aim of hitting full volume production in Q1 2008, and seeing them in PCs thereafter.

[DaLa @ Nov 6th 2007 10:12AM]

Great. Another chip I need to flash firmwares and update drivers on!

[MacGyver @ Nov 6th 2007 10:48AM]

I'm not really sure why this particular chip is receiving attention... power factor correction (PFC) chips have been around for quite some time. In years past PFC was done with discrete components (particularly at large factories that had large inductances, such as motors) using huge capacitor banks. These chips do it on a smaller level and in a smarter fashion.

An ambiguous choice of words with "The chips... effectively determine the amount of power an application will need and optimize accordingly", and maybe that's where the confusion lies. When they say "application", they don't mean Excel or Photoshop, they mean the computer is the application.

[Crayola @ Nov 6th 2007 11:09AM]

This is a super charge PFC controller! It has a bleedin' DSP with 'patented' control algorithm, it may even juggle bowling pins if asked to.

http://www.marvell.com/products/power/pfc_controllers/88em8011.jsp

[why not the LS2/LS7? @ Nov 6th 2007 11:57AM]

Not the world's best description of PFC.

AC power has a cycle to it, this cycle repeats at 60Hz. If a system needs power, it would do best to draw it the peak of the cycle where the most voltage is available. But instead, due to various factors, most devices typically end up drawing a bit after the big peak. And thus there is less voltage available. And with less voltage available they draw more current. This means they draw more current than they need to.

You aren't really charged extra for this extra current, as you pay for power and you're not taking more power, just more current. So the electric company has to produce more current but without getting more money. More current also means they have to put up more wires (more capacity).

So it maximizes system efficiency if your devices are all power factor corrected, so they draw at the best times. The EU requires all computer power supplies to be power factor corrected, but in the US it is optional. Good power supplies in the US are PFC, cheaper ones are not.

I believe to get the Energy Star rating now a device has to be power factor corrected. A good power supply will be over 95% power factor corrected (99% is not uncommon), a non-corrected one will be as little as 40-60% PFC, meaning it draws about twice as much current as it needs to.

To those above, you don't have to firmware update this, it has to be in the power supply, and right now (until NVidia's new ESA), your computer has no communication with the power supply, so there would be no way to flash it anyway.

[MacGyver @ Nov 6th 2007 12:56PM]

Contrary to what the specs lead people to believe, you're simply not going to see 99% efficiency while any appreciable power is being pulled. Other than that, I give your attempt at a layman's description of PFC a thumbs up...

On a side note, most of the PDA/cellphone chargers are non-PFC and are typically in the 40-60% efficiency range.

[Frankenstein Black @ Nov 6th 2007 11:58AM]

Man, could really use this in my AMD 4x4. That rig is a POWER BEAST! Is it a bad think when I turn it on and me and my neighbor's lights dim slightly for a second during boot up?

[psychicist @ Nov 6th 2007 9:08PM]

Instead of coming up with this kind of nonsense couldn't they just get partners to launch computers with PXAxxx chips. That way power consumption could be dramatically lowered without resorting to stupid tricks.